Question

1 is the multiplicative identity for……………..
A. whole numbers
B. integers
C. rational numbers
D. all of the above

Answer 1

Hint: In order to solve this problem one needs to know that multiplicative identity is an identity element (such as 1 in the group of rational numbers without 0) that in a given mathematical system leaves unchanged any element by which it is multiplied.

Complete step-by-step answer:
We know that whole numbers are a subset of integers which in turn are a subset of rational numbers. Also, 1 is the multiplicative identity for rational numbers because the product of 1 and any rational number is the rational number itself.
Thus, 1 is the multiplicative identity for whole numbers, integers and rational numbers.
Hence, the correct option is C.

Note: In this problem you just need to know that rational numbers are represented in p/q form where q is not equal to zero and when it is multiplied by 1 it gives that particular rational number only. Knowing these things will solve your problem.